Many battery-powered devices, such as doorbells and security cameras, are placed in outdoor environments and are exposed to temperature changes. Temperature extremes (e.g., low temperature, such as −30° Celsius) can degrade the performance of the batteries in these devices. For example, the batteries cannot supply power due to severely diminished capacity in the cold and cannot be recharged. This degradation, even though not permanent, may hinder the device's ability to perform its function, for example, to take a picture/video of a potential intruder, using the camera.
The following summary presents a simplified summary of certain features. The summary is not an extensive overview and is not intended to identify key or critical elements.
Systems, apparatuses, and methods are described for warming one or more batteries in a battery-operated device, such as a video doorbell. For example, the warming may be fast (e.g., within a few seconds). A power discharge circuit (or heating element) may be used to heat the battery's core directly and internally by forming a temporary (or pulsed) short circuit between a positive electrode and a negative electrode of the battery. Such short circuit may warm the battery significantly within seconds. Additionally, a variable power resistor may be connected between the positive electrode and the negative electrode. A computing device (e.g., a microprocessor) may be used to control the temporary short circuit so that a fuse connected to the battery does not activate and there is time to charge a capacitor (e.g., a supercapacitor) which supports a control circuit. For example, the short circuit may be formed periodically by connecting the positive electrode and the negative electrode for a period of time (e.g., 0.3 seconds) and disconnecting the positive electrode and the negative electrode for another period of time (e.g., 1 second). A temperature of the battery may be monitored by using a temperature sensor. The temperature sensor may be positioned directly on the negative electrode for direct battery temperature reading.
Heating of the battery may be triggered if the temperature of the battery is below a minimum operational threshold (or a first threshold) and if motion is detected. The video doorbell may turn on camera functions and take pictures/video, if the temperature of the battery is above (e.g., immediately above) the minimum operational threshold. In this way, for example, an approaching burglar may get his/her image captured within seconds even in cold weather (e.g., −30° C.). The battery may continue to be warmed by the power discharge circuit and/or another heat source (e.g., house power), and may be further warmed through fast or high-rate charging, if the temperature of the battery is above a minimum charging threshold (or a second threshold, e.g., 0° C.).
These and other features and advantages are described in greater detail below.
Some features are shown by way of example, and not by limitation, in the accompanying drawings. In the drawings, like numerals reference similar elements.
The accompanying drawings, which form a part hereof, show examples of the disclosure. It is to be understood that the examples shown in the drawings and/or discussed herein are non-exclusive and that there are other examples of how the disclosure may be practiced.
The communication links 101 may originate from the local office 103 and may comprise components not shown, such as splitters, filters, amplifiers, etc., to help convey signals clearly. The communication links 101 may be coupled to one or more wireless access points 127 configured to communicate with one or more mobile devices 125 via one or more wireless networks. The mobile devices 125 may comprise smart phones, tablets or laptop computers with wireless transceivers, tablets or laptop computers communicatively coupled to other devices with wireless transceivers, and/or any other type of device configured to communicate via a wireless network.
The local office 103 may comprise an interface 104. The interface 104 may comprise one or more computing devices configured to send information downstream to, and to receive information upstream from, devices communicating with the local office 103 via the communications links 101. The interface 104 may be configured to manage communications among those devices, to manage communications between those devices and backend devices such as servers 105-107 and 122, and/or to manage communications between those devices and one or more external networks 109. The interface 104 may, for example, comprise one or more routers, one or more base stations, one or more optical line terminals (OLTs), one or more termination systems (e.g., a modular cable modem termination system (M-CMTS) or an integrated cable modem termination system (I-CMTS)), one or more digital subscriber line access modules (DSLAMs), and/or any other computing device(s). The local office 103 may comprise one or more network interfaces 108 that comprise circuitry needed to communicate via the external networks 109. The external networks 109 may comprise networks of Internet devices, telephone networks, wireless networks, wired networks, fiber optic networks, and/or any other desired network. The local office 103 may also or alternatively communicate with the mobile devices 125 via the interface 108 and one or more of the external networks 109, e.g., via one or more of the wireless access points 127.
The push notification server 105 may be configured to generate push notifications to deliver information to devices in the premises 102 and/or to the mobile devices 125. The content server 106 may be configured to provide content to devices in the premises 102 and/or to the mobile devices 125. This content may comprise, for example, video, audio, text, web pages, images, files, etc. The content server 106 (or, alternatively, an authentication server) may comprise software to validate user identities and entitlements, to locate and retrieve requested content, and/or to initiate delivery (e.g., streaming) of the content. The application server 107 may be configured to offer any desired service. For example, an application server may be responsible for collecting, and generating a download of, information for electronic program guide listings. Another application server may be responsible for monitoring user viewing habits and collecting information from that monitoring for use in selecting advertisements. Yet another application server may be responsible for formatting and inserting advertisements in a video stream being transmitted to devices in the premises 102 and/or to the mobile devices 125. The local office 103 may comprise additional servers, such as the remote management (“Mgt”) server 122 (described below), additional push, content, and/or application servers, and/or other types of servers. The remote management server 122 may be configured to manage devices in the premises 102, for example, temperature-sensitive devices such as doorbells and one or more batteries associated with the doorbells. Although shown separately, the push server 105, the content server 106, the application server 107, the remote management server 122, and/or other server(s) may be combined. The servers 105, 106, 107, and 122, and/or other servers, may be computing devices and may comprise memory storing data and also storing computer executable instructions that, when executed by one or more processors, cause the server(s) to perform steps described herein.
An example premises 102a may comprise an interface 120. The interface 120 may comprise circuitry used to communicate via the communication links 101. The interface 120 may comprise a modem 110, which may comprise transmitters and receivers used to communicate via the communication links 101 with the local office 103. The modem 110 may comprise, for example, a coaxial cable modem (for coaxial cable lines of the communication links 101), a fiber interface node (for fiber optic lines of the communication links 101), twisted-pair telephone modem, a wireless transceiver, and/or any other desired modem device. One modem is shown in
The gateway 111 may also comprise one or more local network interfaces to communicate, via one or more local networks, with devices in the premises 102a. Such devices may comprise, e.g., display devices 112 (e.g., televisions), other devices 113 (e.g., a DVR or STB), personal computers 114, laptop computers 115, wireless devices 116 (e.g., wireless routers, wireless laptops, notebooks, tablets and netbooks, cordless phones (e.g., Digital Enhanced Cordless Telephone-DECT phones), mobile phones, mobile televisions, personal digital assistants (PDA)), landline phones 117 (e.g., Voice over Internet Protocol-VoIP phones), and any other desired devices. Example types of local networks comprise Multimedia Over Coax Alliance (MoCA) networks, Ethernet networks, networks communicating via Universal Serial Bus (USB) interfaces, wireless networks (e.g., IEEE 802.11, IEEE 802.15, Bluetooth), networks communicating via in-premises power lines, and others. The lines connecting the interface 120 with the other devices in the premises 102a may represent wired or wireless connections, as may be appropriate for the type of local network used. One or more of the devices at the premises 102a may be configured to provide wireless communications channels (e.g., IEEE 802.11 channels) to communicate with one or more of the mobile devices 125, which may be on- or off-premises. A video doorbell 126, or other security device, may be installed for monitoring the premises 102a, and may communicate with remote management server 122 to, for example, provide uploads of security events captured by the video doorbell 126. The video doorbell 126 may be a wireless device 116.
The mobile devices 125, one or more of the devices in the premises 102a, and/or other devices may receive, store, output, and/or otherwise use assets. An asset may comprise a video, a game, one or more images, software, audio, text, webpage(s), and/or other content.
Although
The video doorbell 126 may comprise a camera (e.g., one or more image sensors) 301. The camera 301 may comprise one or more image sensing devices that comprise, for example, array of photosensitive elements (e.g., an array of charged-coupled device (CCD) and/or complementary metal oxide semiconductor (CMOS) elements), memory, and one or more processors and that may be configured to capture images using visible and/or invisible (e.g., infrared) light. Captured still and/or moving images (e.g., videos) may be sent by a doorbell controller (e.g., doorbell controller 350) to a remote destination, such as remote management server 122, via a data connection such as a wired or wireless network connection (e.g., wired connection 101, wireless connection via access points 127, etc.), which may in turn send the captured images to a homeowner's phone, to a security monitoring system, or any other desired destination. The camera 301 may also, or alternatively, comprise an ambient light sensor to detect an amount of light in the environment. The ambient light may be used, for example, to distinguish between day and night modes for image capture (e.g., night mode may use infrared image capture, while daytime modes may use visible light image capture). The camera 301 may also include one or more audio sensors (not shown) to capture sounds, and audio may be included with the video described herein. The camera 301 may comprise any other sensors if applicable.
The video doorbell 126 may comprise one or more motion sensors 302 to detect motion in a proximity of the doorbell. The motion sensor 302 may comprise passive infrared (PIR) sensor or any other motion sensor that may apply (e.g., radar, etc.). Information indicating motion in the proximity of the doorbell may be sent to the doorbell controller 350 (e.g., one or more of device controller 207, processor 201, etc., in
The video doorbell 126 may comprise a button 303 that a visitor is to press when wishing to announce their presence at the premises 102a. Pressing the button 303 may cause one or more house chimes (not shown) to make a sound such as a ringing bell. The house chimes may be traditional doorbell chimes in a house, and may be powered by the house's power network, such as AC power (e.g., house power 310). One or more speakers (e.g., speaker 214) may be used to connect to the chimes and play a sound based on the button 303 being pressed. Alternatively, the button 303 may be removed. The video doorbell 126 may activate the chimes based on other conditions, such as imaging action of the camera 301, detection of significant motion, remote control, etc. The chimes may serve various purposes other than notifying the presence of a visitor, for example, alerting the homeowner of significant activities near the door, intimidating potential intruders and/or animals, etc. Further functions may be triggered based on the activation of chimes, detection of motion, or other conditions. For example, security cameras inside and/or outside the premises 102a, not limiting to doorbell cameras, may be activated based on motion detected by the video doorbell 126.
The video doorbell 126 may further comprise one or more batteries (“battery”) 330 to provide electrical power for at least the camera 301. Using batteries to power the camera 301 may have advantages such as continuous operation even during power outages. The battery 330 may be rechargeable, and may receive power from the house power 310 via an AC-to-DC converter (not shown). The battery 330 may be non-rechargeable. The battery 330 may be cylindrical battery (e.g., 21700 battery, 18650 battery, etc.). The battery 330 may be pouch or flat battery (e.g., solid-state battery, square battery, etc.). The battery 330 may be any other battery that may apply to the video doorbell 126 to support the functions of its components (e.g., camera 301) and that may be negatively affected by cold weather operation. At least some battery chemistries may exhibit degraded performance if the battery is subjected to temperatures that are outside of a desired range. For example, the optimal operating temperature for a lithium-ion battery may be around 20° C. (e.g., between 15° and 35° Celsius). Such a battery cannot be recharged if the temperature drops below 0° C., and may cease to operate altogether if the temperature reaches −20° C. This may lead to compromised security as the battery-powered camera 301 cannot operate at a low temperature and images cannot be taken when needed (e.g., for a potential intruder). The battery 330 and/or its related circuit/component may be located inside the video doorbell 126. Alternatively, the battery 330 and/or its related circuit/component may be located at least partially outside the video doorbell 126.
The video doorbell 126 may comprise one or more temperature (“temp”) sensors 320 to detect the temperature of the battery 330. The temperature sensor 320 may be positioned directly on the battery 330, for example, on a metal surface of a negative electrode of the battery 330 (e.g., cylindrical battery). If the battery 330 is a pouch battery with integrated temperature sensors, the temperature sensor 320 may be an internal temperature sensor that is already in the pouch battery. Alternatively, the temperature sensor 320 may be an external temperature sensor located on a pouch battery. By placing the temperature sensor directly on the electrode or using the internal temperature sensor, direct battery temperature reading may be realized. Such reading may be more accurate than that obtained based on temperature sensors adjacent to the battery 330 (e.g., on a small circuit board above or next to the battery) which actually reads ambient battery temperature, although such adjacent temperature sensors may also, or alternatively, be used. The temperature sensor 320 may be powered by the battery 330, the house power 310, and/or other power sources such as a capacitor (e.g., capacitor 410).
The video doorbell 126 may comprise a power discharge circuit (or heating element) 340 to warm the one or more batteries 330. For example, the warming may be quick (e.g., within a few seconds). Capacity of a battery at least partially returns, for example, if the battery temperature is raised to a certain level (e.g., above −20° C., at 0° C., etc.). The house power 310 may be used to heat the batteries, cameras, etc. For example, the house power 310 (e.g., 2 Watts) may power an external heat generator (e.g., second heat source 460 in
The power discharge circuit 340 may generate heat inside the battery 330 to heat the battery 330, and may increase the temperature of the battery 330 significantly within a few seconds. If the battery 330 is short-circuited, then internal resistance of the battery will produce heat as the battery discharges due to the short circuit. For example, a lithium-ion battery may include a small amount of internal resistance, and this internal resistance may produce heat based on the current that the battery provides. If the battery is short-circuited, then this current becomes very large, and the current flowing through that internal resistance will produce heat. Also, the ion/electron transfer (the chemical reaction) in discharging a lithium-ion battery will also produce heat from the chemical reaction. A short circuit may stress the battery, but if the short circuit is only maintained for a very brief duration, the damage to the battery may be minimized, while some heat may be quickly produced. The power discharge circuit 340 may form a short circuit with or without load and may discharge the battery 330 using the short circuit to generate heat. The power discharge circuit 340 may be used alone or in combination with external heat sources (e.g., heat generated by using the house power 310). The power discharge circuit 340 may also generate heat outside the battery 330 (e.g., if there is load, and the load may generate heat due to its resistance), and the external heat may be used to warm the battery 330 as well. The operation of the power discharge circuit 340 may be controlled by the doorbell controller 350 which may be powered by the house power 310 and/or other power sources such as a capacitor (e.g., capacitor 410).
The video doorbell 126 may comprise various other components or elements not shown herein for clarity purpose (e.g., to avoid cluttering in
In
When the power discharge circuit 340 is operating, the switch 420 and the switch 421 may be automatically controlled to change ON/OFF positions in a high frequency. For example, the switch 420 may be ON for a period of time (e.g., 0.3 seconds), while the switch 421 is OFF during the same period of time. In this short period, the power discharge circuit 340 is enabled, and the capacitor 410 is not connected to or charged by the battery 330. Then the switch 420 may be OFF for a period of time (e.g., 1 second), and the switch 421 is ON during the same period of time. In this short period, the power discharge circuit 340 is disabled, and the capacitor 410 is connected to or charged by the battery 330. More details will be described below with respect to individual figures of
In
In
In
In
In step 510, temperature of a battery (e.g., battery 330) may be monitored. For example, information indicating the temperature of the battery 330 may be received from the temperature sensor 320. As described above, the temperature sensor 320 may be positioned directly on or inside the battery 330, so that the battery temperature rather than an ambient temperature may be detected. The temperature sensor 320 may be connected to and communicate with a control circuit, for example, the doorbell controller 350, via wire or wirelessly. The battery temperature to be monitored may comprise a temperature range depending on the battery 330. For example, for a typical Li ion battery, the temperature range may be from −35° C. to 60° C. Alternatively, the temperature range may have no limit or only be limited by the capability of the temperature sensor 320. Although not explicitly shown in
In step 520, a determination may be made as to whether the temperature of the battery 330 is below a first threshold (e.g., minimum operational threshold). The first threshold may be a temperature at or above which the battery 330 functions. A voltage and capacity of the battery 330 will diminish as the battery temperature decreases. Table 2 below shows example temperature versus voltage/capacity for a camera battery. For example, a fully charged battery 330 may only have 5% of capacity at the temperature of −30° C., which may not be enough to support the functions of a camera (e.g., camera 301). At the temperature of −20° C., the battery 330 may have increased its capacity to 10%, which may start to support some functions. The first threshold may be determined based on the battery type, size, percentage of charge, and needed capacity of a desired function, etc. and may be programmed into a controller such as the doorbell controller 350. The first threshold or minimum operational threshold may vary greatly among different desired functions. For example, for the example battery in Table 2, −20° C. may be a minimum operational threshold for simple functions such as sensor function, while a more complex function such as camera function may need a higher minimum operational threshold. If there are more than one desired functions which require different minimum operational thresholds, a lower minimum operational threshold may be selected as the first threshold. If no function is specified, the first threshold may be a minimum temperature for normal operation of the battery 330. Optionally, a determination may be further made as to whether the temperature of the battery 330 is above a critical threshold (e.g., −40° C. or other temperature). The critical threshold may be a temperature at or below which the battery 330 may be too damaged or frozen to be revived even with short circuit. The critical threshold may be determined based on the battery type, size, etc., and may be programmed into a controller such as the doorbell controller 350.
In Table 2, the battery voltage/capacity at each temperature is based on a fully charged battery. If the battery is not fully charged, for example, is half charged, the voltage/capacity at each temperature may be reduced by half. For example, at −20° C., to send a signal to ring a doorbell chime (20% capacity needed), it may need to warm the battery to −10° C. for a fully charged battery. If the battery is half charged, it may need to warm the battery to 10° C.
If the temperature of the battery 330 is below the first threshold, then in step 530, periodic heating of the battery 330 may be performed by using a short circuit (e.g., a pulsed short circuit). For example, the power discharge circuit 340 as shown in
In Table 3, the column “Momentary Short Circuit” lists time needed for each temperature increase for an example battery. A comparison is also provided by the column “External Heater”. For example, it may use 2 seconds to increase the battery temperature from −35° C. to −30° C. using the momentary short circuit. In comparison, if using an external heater (e.g., by house power 310) to heat the battery, it may take 15 minutes. As the battery temperature increases, it may take less time for the momentary short circuit to achieve the temperature rise. For example, it may take 1 second to increase the battery temperature from 0° C. to 10° C. using the momentary short circuit. The numbers in Table 3 are only examples and are shown to demonstrate the momentary short circuit method. These numbers are by no means limitative.
As shown in the example Table 2 and Table 3, the battery voltage and capacity increase along with an increased temperature. Increased voltage and capacity may enable the battery 330 to perform desired functions for devices (e.g. camera 301) that it supports.
Though not shown, step 530 may be performed together with a second heat source (e.g., second heat source 460) if applicable. The second heat source 460 may serve as a supplemental heat source. If the battery temperature exceeds the first threshold, the second heat source 460 may optionally be a main heat source (e.g., the power discharge circuit 340 may be optionally turned OFF in some situations).
Alternatively, if the temperature of the battery 330 is not below (e.g., at or above) the first threshold, or if the temperature of the battery 330 is not above the critical threshold, then in step 510, the battery temperature continues to be monitored. The periodic short circuit heating as described with respect to step 530 is not performed, as the battery 330 may be considered to either have enough capacity to support desired functions or be so damaged that it is not functional. As mentioned above, the house power 310, if available, may help with keeping the battery temperature above the critical threshold.
In step 540, a determination may be made as to whether the temperature of the battery 330 has increased to a second threshold. The second threshold may be a minimum charging threshold (or “charging threshold”) at or above which the battery 330 is rechargeable. For example, the second threshold may be 0° C. The second threshold may be determined based on battery properties, etc. and may be programmed into a controller such as the doorbell controller 350.
If the temperature of the battery 330 has not reached the second threshold, then in step 530, battery heating may be continued to increase the battery temperature. A higher battery temperature may release more capacity/voltage from the battery 330, and in some situations, the battery 330 may need to be recharged in order to support certain desired functions continuously.
If the temperature of the battery 330 has reached the second threshold, then in step 550, high-rate charging for the battery 330 may be performed. As described above, high-rate charging may generate excessive heat in the battery 330 and is usually not recommended. However, the heat may be used to further boost the temperature of the battery 330. When the battery 330 is rechargeable (e.g., at or above the second threshold), the battery 330 may be recharged to add power and to be warmed further if the recharging is at a high rate. Alternatively, a normal-rate charging may be performed. The battery 330 may be further warmed by using the power discharge circuit 340 (e.g., the highly efficient pulsed short circuit) and/or the second heat source 460. Alternatively, the power discharge circuit 340 and/or the second heat source 460 may be turned off. In a situation where recharging the battery is not possible (e.g., no house power, non-rechargeable battery, etc.), step 540 and/or step 550 may be removed. The heating in step 530 may be ceased, if either the first threshold or the second threshold or any other desired temperature threshold is reached.
In step 610, a temperature of a battery (e.g., battery 330) of a doorbell (e.g., video doorbell 126) may be monitored, and motion in a proximity of the doorbell may be monitored. For example, information indicating the temperature of the battery 330 of the video doorbell 126 may be received from the temperature sensor 320. Information indicating motion in the proximity of the video doorbell 126 may be received from the motion sensor 302. Although not explicitly shown in
In step 620, a determination may be made as to whether motion is detected in the proximity of the doorbell. For example, PIR sensors may detect changes in infrared radiation emitted by objects in their field of view. When a person or object moves within the sensor's detection range, it causes a change in the infrared energy pattern. When the PIR sensors detect a rapid change in the infrared pattern, a motion detection may be triggered.
If motion is detected in the proximity of the doorbell, then in step 630, a further determination may be made as to whether the battery 330 is warm enough to be used. Alternatively, if motion is not detected in the proximity of the doorbell, then in step 610, the monitoring of the temperature and motion may continue.
In step 630, a determination may be made as to whether the battery 330 is warm enough to be used. For example, if the temperature of the battery 330 is above a first threshold (e.g., the first threshold as mentioned in step 520 in
If the battery 330 is warm enough to be used (e.g., battery temperature exceeding the first threshold), then in step 660, functions of a camera (e.g., camera 301) of the doorbell (e.g., video doorbell 126) may be turned on. Camera functions may comprise taking pictures, recording a video, etc. As described above, camera functions may be turned on based on detection of motion. Since motion is detected, the camera may capture images of the person, animal, or other object causing the motion.
Alternatively, if the battery 330 is not warm enough to be used, then in step 640, warming of the battery 330 may be performed. For example, pulsed heating (e.g., by using pulsed short circuit) of the battery 330 by a power discharge circuit 340 may be performed. Details of such heating have been described above (e.g., with respect to step 530) and will not be repeated herein. In the example of
In step 650, a determination may be made as to whether the battery 330 is warm enough to be used. If the temperature of the battery 330 is above the first threshold, the battery 330 may be considered as warm enough to be used; then in step 660, functions of the doorbell such as camera functions may be turned on. Alternatively, if the battery 330 is not warm enough to be used, the heating of the battery 330 may continue in step 640.
In step 670, a determination may be made as to whether the battery 330 is warm enough to be charged. For example, if the temperature of the battery 330 is above a second threshold (e.g., the second threshold as mentioned in step 540 in
If the battery 330 is warm enough to be charged, then in step 680, high-rate charging for the battery 330 may be performed, similar to step 550 in
In
The battery or batteries as mentioned in this specification may have applications other than doorbells, as long as those applications need fast warming of the battery in a cold environment. For example, the battery and its heating circuits may be used in the outer space (e.g., spacecraft, etc.), transportation (e.g., electric vehicles, etc.), the refrigeration industry, winter/high-elevation sports, etc., and may be quickly warmed using its own power (or self-warmed) to perform desired functions. Although the examples mention rechargeable batteries, non-rechargeable batteries may also apply.
Although examples are described above, features and/or steps of those examples may be combined, divided, omitted, rearranged, revised, and/or augmented in any desired manner. Various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this description, though not expressly stated herein, and are intended to be within the spirit and scope of the disclosure. Accordingly, the foregoing description is by way of example only, and is not limiting.